According to a study published in the December 28, 2016, online issue of Neurology, the medical journal of the American Academy of Neurology, welders are at a higher risk of developing Parkinson’s and Parkinson’s like symptoms that may worsen with the exposure to manganese, which is a toxic chemical element present in welding fumes.
Brad A. Racette, MD, of Washington University School of Medicine in St. Louis, Mo., and a Fellow of the American Academy of Neurology, who serves as the study’s lead author said, “These welders are developing parkinsonian symptoms even though their exposure to manganese is below the current regulatory limits.
This study suggests that we need more stringent workplace monitoring of manganese exposure, greater use of protective equipment and monitoring and systematic assessment of workers to prevent this disabling disease.”
Welding has been associated with parkinsonism, which is a generic term used to define a class of disorders that cause movement problems similar to those observed in Parkinson’s disease.
These symptoms include slow movement and stiffness among other limitations.
The study included 886 Midwestern workers who served as trial subjects, from two shipyards and a heavy machinery fabrication shop.
Neurologists who have specialized in movement disorders examined the participants at the start of the study. 398 of the participants were followed for up to 10 years to assess for the presence or absence of Parkinson’s symptoms.
The scientists used a questionnaire to assess the workers’ exposure to manganese. The questionnaire included questions about their job types and duration of time on the job.
15% of the participants which equalled 135 workers suffered from parkinsonism, with scores of 15 on a scale of zero to 108 points.
The scientists discovered that cumulative manganese exposure was associated with an annual increase in scores on a movement test.
Each additional milligram of manganese per cubic meter per year added an average estimated 0.24 points on movement problems scale.
Therefore, this meant that the more a person was exposed to toxic welding fumes, the more likely was he to suffer from Parkinson’s and to a greater extent, his movement would be impaired.
Racette added that as an example if a welder who had worked for 20 years before he was examined for the first time had an average estimate of 2.8 milligrams manganese per cubic meter per year exposure.
He was going to have an approximate seven-point further increase on the movement test associated to that welding fume exposure.
According to the scientists, the results were similar after adjusting for other variables, such as drinking alcohol, pesticide exposure, and smoking, which can have a significant impact on a person’s movement and mobility.
The scientists added that the symptoms that worsened with cumulative manganese exposure were slowing of arm and hand movement, arm and leg stiffness, speech problems and facial expression getting hampered.
The association between an increase in Parkinson’s symptoms and exposure to welding was even more concrete in welders who conducted flux core arc welding, the welding technique that produces the highest levels of particulate matter, in a tiny space.
The association was stronger in workers who has been tested within 5 years of them starting welding.
According to Racette, this might be due to the fact that workers with greater exposure may develop Parkinsonism and have to drop out of their profession.
Racette further added that unfortunately they were not able to directly measure workers’ cumulative manganese exposure.
He also noted that his team could not dismiss the impact of other metals in the welding fumes or exposure to other toxic chemicals, such as paint or degreasing solvents.
Previous studies have also shown a strong association between toxic elements such as manganese, lead and copper, and onset and progression of Parkinson’s.
The exact reason why this link exists is not known, but it has been theorized that these metals impact the brain nerve pathways in a way that leads to Parkinsons.
Parkinson’s disease is an incurable neurodegenerative disease that results in the rapid death of nerve cells, that causing tremors of the hand, jaw, face, legs and torso.
It is the second most common neurodegenerative disease after Alzheimer’s and impairs balance, co-ordination and motor skills.
Most Parkinson’s patients are 60 years or older but early-onset Parkinson’s disease affects people aged from 21-40 while juvenile-onset Parkinson’s affects individuals less than 21 years of age.
The number of Parkinson’s patients is going to increase over the coming years due to greater life expectancy.
Most Parkinson’s disease symptoms related to motor skills occur due to a lack of dopamine from a loss of dopamine-producing cells in the brain.
When dopamine levels fall substantially, the communication between the brain and the area of the brain that controls movement becomes impaired, worsening overall movement.
Other cells in the brain can also degenerate, causing non-movement related symptoms.
It is unclear as to why dopamine cells degenerate but studies have shown that stress, genetics and environment are responsible.